Inverse Kinematics in BGE not working
Just quoting one solution that Daedalus_MDW gave me in another thread.

to solve your issue, you need to make the armature a parent of the mesh. but then collision wont work. heres how it should look.
-&gt; simple collision mesh (low poly invisible physics)
-v&gt; armature
--v&gt; visual mesh (pretty hires stuff)
make sure everything is at (0,0,0) location, otherwise unusual things may occur.

It worked as expected :)